From StarWars.com:
"Anyone lucky enough to be on the holiday mailing list of a Lucasfilm division employee this year may soon find a cool new Star Wars-themed card arriving in their mailbox. An annual tradition since the '70s, Lucasfilm has created a different holiday card each year for corporate friends and colleagues, with Star Wars a popular theme throughout the years.

This year, recipients will open their card to three lines of caroling stormtroopers, courtesy of ILM Production Assistant for the Art Department Lorraine LeBer."

To find out more, check out StarWars.com, and look for a checklist of past years' cards coming soon.